There are many kinds of industrial machines having components which move relatively toward and away from one another during operation to perform one of a number of operations on a workpiece supported between the relatively movable components. Examples of such machinery are punch presses, forming and drawing die presses, and progressive die machines. In all of such machinery it is conventional practice, prior to commencing a production run, for the machine operator to adjust the relatively movable die members or the like for proper registration, manually place a workpiece in position between the relatively movable parts, and cycle the machine under manual control to verify proper adjustment of the relatively movable parts.
In the case of a progressive die machine there conventionally is a plurality of pairs of die members spaced along a path that is to be traversed by a strip or ribbon of workpiece-forming material. Each pair of relatively movable dies constitutes a work or forming station and it is conventional for the ribbon material to be unwound from a reel, advanced incrementally into each station, and rewound on a second reel.
Preparatory to commencing a production run of a progressive die machine, the die registration steps referred to earlier are performed at each station. In addition, the leading end of a ribbon of material conventionally is advanced by hand to each successive station during the preliminary machine setup operation. Further, when one reel of ribbon material has been exhausted following a production run, it is conventional for the leading end of a fresh ribbon material to be moved manually incrementally from station to station preparatory to automatic operation of the machine.
In each of the foregoing cases the operator of a machine is exposed to substantial risk of injury in the event the relatively movable parts of the machine are caused to move while one or the other of the operator's hands is within the machine. Such risk is increased in those instances in which the operator is weary or becomes careless.
An object of the present invention is to provide apparatus capable of manipulating a workpiece supported by a machine and which is constructed in such manner as to ensure that the machine cannot be cycled unless both hands of the operator are positioned on the manipulating apparatus and in a safe position external of the machine.